Little Gem slowly dying - HELP!

This Little Gem magnolia was a 30-gallon tree planted approximately 6 years ago. It did well for a couple of years, but then leaf production started to drop off, and this year it is looking incredibly sparse. I asked about it at the nursery where the tree was purchased and was told this is simply the tree's natural cycle of dropping leaves and growing new ones, but that doesn't explain why overall leaf production (and flowers) have consistently decreased over the years. I am wondering if it is root-bound, or maybe just not getting enough water, or what? I'm considering hiring someone to have the tree moved closer to the house, in an effort to save it, as any trees planted this far out have not seemed to do as well (so maybe it's the soil? I think it's pretty alkaline.) I would welcome any thoughts/ideas!

Well that's definitely not normal spring leaf drop. It looks like it's planted in rocks? Probably a combination of improper planting and drought stress. Trees don't get more sparse and sprindly as they get established, it's the other way around. My guess is you'll find out what the problem is when you go to transplant it. Not the time to try to transplant it by the way. Too hot.